1. 簡介
Jetty 提供了一個Web服務器和javax.servlet容器，以及對HTTP/2，WebSocket，OSGi，JMX，JNDI，JAAS和許多其他集成的支持。這些組件是開源的，可用於商業用途和發行。
Jetty有一個口號：不要把應用部署到Jetty上，要把Jetty部署到你的應用裏。這句話的意思是把應用打成一個war包部署到Jetty上，不如將Jetty作爲應用的一個組件，它可以實例化並像POJO一樣。換種說法，在嵌入式模塊中運行Jetty意味着把HTTP模塊放到你的應用裏，這種方法比把你的應用放到一個HTTP服務器裏要好。
2. 簡單使用
添加 jetty-server 依賴
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-server</artifactId>
<version>9.4.19.v20190610</version>
</dependency>
繼承 AbstractHandler
public class HelloHandler extends AbstractHandler {
@Override
public void handle(String s, Request request, HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws IOException, ServletException {
// 設置類型，指定編碼utf8
httpServletResponse.setContentType("text/html; charset=utf-8");
// 設置響應狀態嗎
httpServletResponse.setStatus(HttpServletResponse.SC_OK);
// 寫響應數據
httpServletResponse.getWriter().write("<h1>HelloHandler</h1>");
// 標記請求已處理，handler鏈
request.setHandled(true);
}
}
創建Server並啓動
public class JettySimpleTest {
public static void main(String[] args) throws Exception {
// 創建服務器
Server server = new Server(8001);
// 設置handler
server.setHandler(new HelloHandler());
// 啓動應用服務並等待請求
server.start();
// 阻塞Jetty server的線程池，直到線程池停止
server.join();
}
}
訪問 localhost:8001
3. 嵌入 web 應用(WebAppContext)
WebAppContext是ServletContextHandler 的擴展，使用標準的web應用組件和web.xml，通過web.xml和註解配置servlet，filter和其它特性。
3.1 hello-war
這裏會創建三個項目，然後打成war包。
添加依賴
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
Hello1Servlet
public class Hello1Servlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// 設置響應內容類型
resp.setContentType("text/html");
// 實際的邏輯是在這裏
PrintWriter out = resp.getWriter();
out.println("<h1> hello-war-1 </h1>");
out.println("<h2> HelloServlet </h2>");
}
}
web.xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<display-name>Hello1Servlet</display-name>
<servlet>
<servlet-name>Hello1Servlet</servlet-name>
<servlet-class>com.shpun.Hello1Servlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Hello1Servlet</servlet-name>
<url-pattern>/hello1</url-pattern>
</servlet-mapping>
</web-app>
index.jsp
<html>
<body>
<h2> hello-war-1 index.jsp </h2>
<h2>Hello World!</h2>
</body>
</html>
hello-war-1 項目結構
hello-war-2 和 hello-war-3 項目結構，和hello-war-1一樣。
3.2 jetty-server
添加依賴
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-server</artifactId>
<version>9.4.19.v20190610</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-servlet</artifactId>
<version>9.4.19.v20190610</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-webapp</artifactId>
<version>9.4.19.v20190610</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-deploy</artifactId>
<version>9.4.19.v20190610</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-annotations</artifactId>
<version>9.4.19.v20190610</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>jetty-servlets</artifactId>
<version>9.4.19.v20190610</version>
</dependency>
<dependency>
<groupId>org.eclipse.jetty</groupId>
<artifactId>apache-jsp</artifactId>
<version>9.4.19.v20190610</version>
<type>jar</type>
</dependency>
JettyServer，獲取war包地址，使用 WebAppContext 封裝。然後再添加到 Server 中。
public class JettyServer {
private final Server server;
public JettyServer() throws Exception {
ClassLoader classLoader = getClass().getClassLoader();
File tempDir = new File("E:\\IDEA_workspace\\jetty-test\\work\\jetty");
// war包文件路徑
File helloWar1 = new File("E:\\IDEA_workspace\\jetty-test\\hello-war-1\\target\\hello-war-1.war");
File helloWar2 = new File("E:\\IDEA_workspace\\jetty-test\\hello-war-2\\target\\hello-war-2.war");
File helloWar3 = new File("E:\\IDEA_workspace\\jetty-test\\hello-war-3\\target\\hello-war-3.war");
// Web應用程序上下文處理程序。封裝工作目錄，war包地址，上下文，類加載器
WebAppContext helloWar1WebAppContext = buildWebApContext(tempDir, helloWar1,"/hello1", classLoader);
WebAppContext helloWar2WebAppContext = buildWebApContext(tempDir, helloWar2,"/hello2", classLoader);
WebAppContext helloWar3WebAppContext = buildWebApContext(tempDir, helloWar3,"/hello3", classLoader);
// 將三個 WebAppContext 添加到一個 HandlerCollection 中。
// HandlerCollection 是一個包含多個處理器的集合，按照順序依次處理
HandlerCollection handlerCollection = new HandlerCollection();
handlerCollection.addHandler(helloWar1WebAppContext);
handlerCollection.addHandler(helloWar2WebAppContext);
handlerCollection.addHandler(helloWar3WebAppContext);
// 將 HandlerCollection 壓縮
GzipHandler gzipHandler = new GzipHandler();
gzipHandler.setIncludedMethods("GET", "POST", "PUT", "DELETE");
gzipHandler.setHandler(handlerCollection);
// HandlerCollection會依次調用每一個Handler，即使請求已經被處理了
ContextHandlerCollection contextHandlerCollection = new ContextHandlerCollection();
contextHandlerCollection.addHandler(gzipHandler);
// HandlerList順序執行handler
HandlerList handlerList = new HandlerList();
handlerList.addHandler(contextHandlerCollection);
// 初始化 Server
QueuedThreadPool threadPool = new QueuedThreadPool(30);
threadPool.setName("Web Server");
server = new Server(threadPool);
server.setHandler(handlerList);
// HTTP 配置，這是設置請求和返回頭的大小
HttpConfiguration httpConfiguration = new HttpConfiguration();
httpConfiguration.setRequestHeaderSize(16384);
httpConfiguration.setResponseHeaderSize(16384);
// 配置連接器
// Connector是Jetty中可以直接接受客戶端連接的抽象，一個Connector監聽Jetty服務器的一個端口
ServerConnector serverConnector = new ServerConnector(server, new HttpConnectionFactory(httpConfiguration));
// 多網卡時使用
//serverConnector.setHost("192.168.1.2");
serverConnector.setPort(8001);
// 設置連接的最大空閒時間
serverConnector.setIdleTimeout(30000L * 2);
server.addConnector(serverConnector);
// 解析jsp方式1：啓用基於註釋的配置，以確保正確初始化了jsp容器
Configuration.ClassList classList = Configuration.ClassList.setServerDefault(server);
classList.addBefore(JettyWebXmlConfiguration.class.getName(), AnnotationConfiguration.class.getName());
}
private void start() throws Exception {
server.start();
}
public static void main( String[] args ) throws Exception {
JettyServer jettyServer = new JettyServer();
jettyServer.start();
}
/**
* 構建 WebAppContext
* @param tempDir
* @param war
* @param contextPath
* @param classLoader
* @return
* @throws IOException
*/
private WebAppContext buildWebApContext(File tempDir, File war, String contextPath, ClassLoader classLoader) throws IOException {
WebAppContext webappContext = new WebAppContext(war.getPath(), contextPath);
webappContext.setContextPath(contextPath);
webappContext.setDisplayName(contextPath);
File workDir = new File(tempDir, war.getName());
webappContext.setTempDirectory(workDir);
webappContext.setClassLoader(new WebAppClassLoader(classLoader, webappContext));
// 解析jsp方式2：
//webappContext.addBean(new JspStarter(webappContext));
//webappContext.addServlet(JettyJspServlet.class, "*.jsp");
return webappContext;
}
}
Jetty解析jsp目前發現有兩種方式
一種是在 Server 啓動前，添加
Configuration.ClassList classList = Configuration.ClassList.setServerDefault(server);
classList.addBefore(JettyWebXmlConfiguration.class.getName(), AnnotationConfiguration.class.getName());
一種是在創建 WebAppContext 時添加
webappContext.addBean(new JspStarter(webappContext));
webappContext.addServlet(JettyJspServlet.class, "*.jsp");
還需要 JspStarter
public class JspStarter extends AbstractLifeCycle implements ServletContextHandler.ServletContainerInitializerCaller {
JettyJasperInitializer sci;
ServletContextHandler context;
public JspStarter(ServletContextHandler context) {
this.sci = new JettyJasperInitializer();
this.context = context;
this.context.setAttribute("org.apache.tomcat.JarScanner", new StandardJarScanner());
}
@Override
protected void doStart() throws Exception {
ClassLoader old = Thread.currentThread().getContextClassLoader();
Thread.currentThread().setContextClassLoader(context.getClassLoader());
try {
sci.onStartup(null, context.getServletContext());
super.doStart();
} finally {
Thread.currentThread().setContextClassLoader(old);
}
}
}
測試，三個war包都可正常部署訪問
參考：
Jetty 官方文檔
Jetty 官方文檔 - 嵌入Jetty
Jetty篇教程 之Jetty 嵌入式服務器
idea下，Jetty採用main方法啓動web項目
內嵌式jetty服務器支持jsp
jetty介紹之handler
Jetty Connector學習筆記